Certain types of LED fixtures can operate in 8-bit or 16-bit modes, where when operating in 16-bit, each property (red, blue, green, white, intensity, etc.) occupies two DMX channels, a coarse and a fine. Whilst obviously when mapping from an 8-bit video source using 16-bit control is pointless, it would still be handy to have to option to specify this as a pixel type. There are lots of situations where it is impractical to change the operating mode of the fixture (there may not be time, the fixture may be rigged and inaccessible, or it may be being used by other systems) so the ability to address fixtures operating in this mode from MadMapper is needed.

If you use materials on fixtures you are working with a floating point source (not a RGB 8 bits per component source, like images, movies or Syphon textures - they are 8 bpc in most cases but MadMapper supports other formats) - so you can have more than 8 bits precision in your source !

I would second this. I use those low-mid range moving head lights and they look a little jerky with 8-bit only. I would be great to have a way to achieve the 16-bit movement (pan, tilt, etc) using software and not having to set all the fixtures by hand, etc.

In MadMapper fixture editor you can make 16 bits channels for red, green, blue, luminosity, or channels controlled with slider etc.
So the 16 bits channel getting the RED value of the shader can be used for a a 16 bits PAN control, the green for tilt etc. If you want to control the pan & tilt with a material shader & the color with another material you can split your fixture in two and set some channels to "unused" in each fixture definition. Then you patch both at the same address. A bit tricky but it opens many possibilities